Apparatus for vacuum-drying temper-ature-sensitive goods



Sept. 20, 1960 J. wENz| 2,952,922

APPARATUS FOR VACUUM-DRYING TEMPERATURE-SENSITIVE GOODS Sef- 20, 1960 J. WENZL 2,952,922

APPARATUS FOR VACUUM-DRYING TEMPERATURE-SENSITIVE GOODS Filed Jan. 4, 1956 2 Sheets-Sheet 2 ilnited rates Patent O fifiice APPARATUS FOR VACUUlVI-DRYING TEMPER- ATURE-SENSITIVE GOODS Josef Wenzl, Harzstieg 1, Braunschweig, Germany, assignor to Walter Jordan, Braunschweig, Germany Filed Jan. 4, 1956, Ser. No. 569,284

Claims priority, application Germany Jan. 13, 1955 4 Claims. (Cl. 34-92) The present invention relates to a novel construction of a chamber of high strength and light weight. Such a chamber is of particular advantage in an apparatus for vacuum-drying temperature-sensitive goods. Such goods are, for example, foam rubber, windings of electric condensers, and so on, which should only be exposed to temperatures below a certain degree. In order to be able to complete the drying process for such substances or goods in an economical manner and within a short time, as high a vacuum as possible is created in the drying apparatus, by withdrawing continuously the moisture driven out of the goods in the form of steam.

The invention, however, is not limited to vacuum chambers, but may advantageously find application in connection 4with other devices, such as cooling installations, etc., where high strength and light weight are important.

In installations requiring high vacuum, the large walls of the apparatus, which consists of an all-enclosed housing, are subjected to considerable strain caused by the external atmospheric pressure. For that reason, the known apparatuses of this kind are of very sturdy construction and need a foundation of masonry. This foundation and the considerable amount of material necessary for the apparatus proper, raise the expenses for construction and transportation, and also the mounting of such a vacuum apparatus.

It is the object of the present invention to provide a chamber construction defining a vacuum chamber which is free of the above mentioned shortcomings. More particularly, to provide a chamber, in which the ratio of eective space to the weight of the apparatus, particularly large apparatus, is more advantageous.

This can be accomplished by decreasing the weight of the apparatus as compared to known devices of this kind. By so doing, considerable amounts of material are saved, whereby the expenses for building and transporting the apparatus to the place, where it is to be used, as well as the mounting expenses will be decreased accordingly.

According to one embodiment of the invention these objects are achieved by providing a chamber construction for a vacuum apparatus which comprises a hermetically closed housing provided with equipment for heating and evacuating, 4as Well as with control elements. The housing is formed of channel-like sections sealed to each other by airtight connections; each section is composed of separate walls, herrnetically joined, and each wall comprises a frame built of a pair of oppositely arranged parallel anges extending parallel to the longitudinal axis of the housing and disposed in its diagonal planes, and another pair of mutually opposed flanges lying in planes perpen- 2,952,922 Patented Sept. 20, 1960 dicular to the longitudinal axis of the housing. These latter flanges have mitered ends corresponding to the inclination of the rst pair of anges, and welded thereto. The iwalls are made of corrugated sheet metal, iilling the frames consisting of the ilanges and being welded thereto.

When the apparatus or the housing thereof is in the form of a square, there will be four walls connected by welding to each other at the lianges arranged at an inclination with respect to the longitudinal axis of the housing, or which are connected by means of screws with intel-position of packing means. One section of the housing is thereby formed as a square-shaped channel-like unit. Depending on the desired total length of the apparatus, a larger or smaller number of such units are combined in an air-tight manner by welding or screwing with interposition of packing materials, the connections being made at the anges disposed at right angles to the longitudial axis of the housing.

The hont and rear ends of the housing are likewise closed by walls, consisting of a frame made of angle irons and a filling welded to the frames, which is made of thin-walled corrugated sheet metal as more fully described hereinbelow.

The external superpressure of about l kg./cm.2 acting on the housing upon application of a vacuum, is taken up by the sheet metal extending between the flanges and transmitted to the iron frames of the housing walls. These frames combine to form a channel-like housing section, support each other by the tlanges inclined approximately about 45 degrees so that in principle all the forces acting toward the interior of the housing, due to the atmospheric pressure, are taken up by these anges placed on edge in the direction of these forces. By wall llings consisting of corrugated sheet metal, the load is absorbed and in addition thereto the frames are placed under stress in their positions.

Furthermore the stability of the apparatus is improved with lowest expenditure of material by subdividing all wall faces into comparatively small separate wall elements, that is to say, making the sheet metal fillings of small width with respect to their enclosing frames.

By combining sections as described and built according to the invention, vacuum-drying apparatus of any desired length can be built. Practical experience has shown that in the most favorable instances the total weight of the vacuum-drying apparatus according to the invention may be reduced to one-third of the weight of a conventional drying apparatus, all other conditions being equal. Vacuum-drying apparatus according to the invention do not need any masonry foundation and they may be mounted in a very appropriate manner on longitudinal beams, a factor which simplifies assembly and takes load oft the connections of the several sections.

The separate walls can be easily manufactured and transported and are readily assembled on location.

The apparatus according to the invention will now be more fully described with reference to the accompanying drawings, but it should be understood that these are vgiven by way of illustration and not of limitation, and that many changes in the details can be made without departing from the spirit of the invention.

In the drawings Fig. 1 is a perspective View of the vacuum-drying apparatus built according to the invention.

Fig. 2 is a partial `section of a vacuum-drying apparatus of diierent design.

Fig. 3 isa partial View of one end of the apparatus.

Fig. 4 is a partial plan view at the two ends of the drying apparatus shown in Fig. 2, and

Fig. 5 is a partial cross section through a vacuum apparatus built up of double walls.

Referring now to Fig. 1, the vacuum-drying apparatus is shown to comprise a more or less elongate housing A, mounted on rails 9 and which is hermetically closed at the frontend Yrear ends by walls B and C. Depending on the length of the housing A, either only wall B is removable as a door, or both walls B and C can be so removed. For this purpose wall B is shown to comprise ears D for receiving hooks D' of chains vE depending from a crane (not shown), sothatthe wall can be moved by the crane Yinto Vthe closedV position as shown in the drawing, or removed from `this position. Between wall B and the end wall of casing A, a packing F is inserted against which wall B is pressed by `atmospheric. pressure in hermetical sealing relationship, asV soony as a vacuum is set up in the casing A.y The door B is provided with pivotally mounted hooks G engaging with pins HzrnountedV at the end wall of casing A, thereby forming ya mechanical connection between B and the end'of casing A. The substances or goods -to be dried may for instance berrolled into ythe casing by carriages (not shown in the drawing) and rails 10 (Fig. 2), are provided for this purpose-in the casing. p

For creating and maintaining a vacuum, the housing A isV provided with a short pipe J, to which may be connected the suction line of a suction pump (not shown). A pressure gauge K mounted on'the housing walls serves for Lthe control of internal pressure within the housing, and View glas-ses L in the wall allow the observation of the goods during the drying procedure.

As a drying means, I may use steam or =hot air which is entered `into a heating coil system O at the bottom of housing A by means yof a pipe N and a connecting line, (not shown in the drawing), while it is allowed to escape by means of a short pipe M and a pipe system, likewise not shown in the drawing.

Instead of using the heating system as described, Aga heating or electrical resistance heating may be used. Since the type of Vheatingis not part of the invention, a further description thereof 'as well as an illustration of the heating system is omitted.

When needed, a coolant can be entered by .N and drained by M from the casing.

According -to the invention the housing A'of the vacuum apparatus is composed of several sections S, yin ithe case illustrated in Fig. l, of three sections which may be joined in 'an airtight manner by welding or by screw connection with interposition of a packing.

Every individual section S consists, according tothe invention, of sepa-rate walls and each wall comprises a square frame consisting of a Vpair of parallel anges 2, 3 extending in the longitudinal direction of thehousing A parallelto the longitudinal axis a thereofV and dis-V posed with their transverse sides in diagonal planes containing the axis a of housing A. Furthermore a second Ipair of parallel iianges 4, 5V are placed iat right angles to flanges 2, 3 lhafving .their transverse sides vin planes per-A pendicular to the longitudinal axis a of housing A and Ih-aving mitered ends so as to correspondwith the'inclination of the flanges 2, 3 with which they are connected by welding. Each section also comprises vat least one wall 6, filling the frame and consisting of thin-walled Vcorrugated sheet metal which is welded to the frame consisting of anges 2, 3, 4, 5. The sheet metal iilling 6 may be concave with respect to the interior of housing A, more particularly it may fbe either ldish-shaped or cylindrical, as shown in Fig. l, or spherical, 6d, -as shown in Figs. 2, 3, and 4. In Fig. 5 a filling 6a, y6b

4 is shown in which the conrugations follow a straight plane.

For a housing A with a at cross section, four such walls are combined to a channel-like section S, in such a manner, that they are welded together with the flanges 2, 3 or screwed together with interposition of a packing material for hermetical sealing. At each end of such a section comprising four walls, the flanges 4, S disposed yat right angles to the longitudinal axisV a of the housing A, will form square ring flanges by which the required nurnber ci 'sections Vcan be combined to a housing A of desired length, the joining being again done by welding or screwing together in hermetical sealing by Vinterposition of packing material.

The walls B and C used for closinglthe end-s of housing A each consist of -a'fram'e made up Yof four welded mitered edges. To the trames, Ya filling of thin-walled sheet metal 8 is likewise joined by welding. In order -to increase ythe strength of the walls, they are formed of several pieces 8a, 8b, 8c, as shown in Figs. l Vand 3. In this case, the sheets 811, Eb, 8c are welded together with anges Sd, which Y:in turn are welded to the angle iron frame 7. The sides of frame 7 whichrlie at a right 'angle with respect to 'the longitudinal axis a of the housing A, form asquare ri-ng `llange Vby means of which the walls B, C, are fastened to the corresponding ring ilanges 4, 5 of the sections VS forming the ends of housing A. Between the angcs of the walls B, C, and those ofV sections S packing material F is inserted when the walls B, C, are removable doors, otherwise the flangesof the wall C and those of adjacent sections S may be Welded together. p

VAll wall and door fillings may, as shown in Fig. 5, be'composed of two frames, consisting of ilanges 2a, 3a, 4a, 5a land -of thin-walled corrugated metal sheets, 6a and 6b, arranged at a certain distance with respect to each other, so that they will form a hollow space which will provide -a good heat insulation .for housing A, or may serve las heating or cooling` space. The hollow spaces of theseveral walls of la section S can be brought into communication by openings 6c, provided in the flanges 2a, 3a.

The V'above described arrangement makes possible the heating of large areas with steam of low tension, sometimes even vacuum waste stearn. When a coolant is used, the double walls will likewise 'be of use.

By building the vacuum-drying apparatus in lightweight construction, about 50% of the materials can be saved, which are usually consumed whenpbuilding according to conventional methods.

What I claim is:

l. A high-strength, light-weight, hermetically sealed chamber-construction deining `a vacuum chamber, comprising Ia plurality of rectangular frames including end frames hermetically connected to each other and forming 'a chamber, each Yof said frames'comprising two pairs of oppositely arranged anges, the first pair of vsaid flanges extending parallel'to the longitudinal axis of said Vchamber and being disposed with the transverse sides yin a diagonal plane of said chamber, the second pair Vof said two pairs-of franges being disposed in planes'perpendicular to the longitudinal axis of said chamber and having mitered ends corresponding to the inclination of said rst pair -of lian-ges and being secured thereto; at 'least one member lof corrugated sheet metal extending between and being secured'to said anges so las to'deiine the kslide wall `of said chamber, a front wall member and a internal pressure of said chamber mounted on one of said frames.

2. The chamber construction :according to claim 1, wherein said members of corrugated sheet metal are disposed in a concave relationship with respect to the interior of said chamber.

3. The chamber construction according -to claim 2, wherein said members of corrugated sheet metal are dish-shaped.

4. The chamber construction according to claim 2, wherein said members of corrugated sheet metal are spherical.

References Cited in the le of this patent UNITED STATES PATENTS Adams et a1. July 4, 1871 Dimmick Feb. 21, 1882 Smith Mar. 26, 1889 Hansen June 21, 1910 Bear Mar. 28, 1911 Rice May 6, 1924 Gentele May 2, 1939 

